并流下行循环流化床反应器气固传质模型

建立了并流下行循环流化床反应器气固吸附传质模型,并采用稳态示踪的实验研究方法,测定了下行床中气相示踪剂浓度的轴向分布,进而利用Marquardt多元非线性回归方法求得了模型参数即轴向扩散系数和传质系数的值.实验结果的回归得到了模型参数与操作条件的经验关联式.该模型能很好的预计传质过程,包括轴向扩散系数和传质扩散系数的值以反应器中组分浓度的轴向分布,因此可用于描述并流下行循环流化床反应器的气固吸附传质过程.

THE MODEL FOR GAS-SOLID MASS TRANSFER IN COCURRENT DOWNFLOW CIRCULATING FLUIDIZED BED

The mathematical model for the gas-solid adsorption mass transfer in a cocurrent downflow circulating fluidized bed(CDCFB) reactor is proposed in this paper. Experiments were conducted for measuring the axial tracer concentration distribution by using the steady-state tracer method. The model parameters, mass transfer coefficient and axial diffusion coefficient were obtained by non-linear retrive method (Marquardt method).The empirical correlations of experimental data for model parameters were obtained, as given by the following equationsPe2 =The model can predict the characteristics of gas ?solid mass transfer and fit the experimental results very well. So the model proposed in this paper could be used to describe the mass transfer in CDCFB.